However, I can't figure out how to set breakpoints, step through the code, add watches, etc. using any of them. I've also tried using the MS Visual Web Debugger 2008 Express Edition, but it doesn't run within the browser and lacks features.

If any of the tools above do provide the JS debugging features I'm seeking, any tips on how to use them effectively would be welcome. Alternatively, feel free to recommend other tools.

Update: In addition to suggesting alternative tools, if someone could confirm that none of the tools above do support setting breakpoints and stepping through JS code in IE6, that would be very helpful.

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